People all over the world of various cultures, religions, and nationalities use their hands to greet one another, communicate through sign language, hold their babies, do work, and more. Hands are a universal part of our humanity, and the hand is one of the most vital parts of the body. Here’s proof: One-fourth of the motor cortex in the brain is dedicated to controlling muscles in your hands. Yet what I’ve learned as a hand surgeon is that many people don’t know a lot about their hands. Here are some hand misconceptions I’ve encountered over the years.

Myth No. 1: If You Can Move Your Finger, Wrist, or Elbow, It Isn’t Broken

Recently, I treated a tough young defensive end who was sure his finger wasn’t broken because he could move it. He insisted on getting back in the game. “Just because you can move it doesn’t mean it’s not broken,” I told him. Only a doctor, using an X-ray, can make the definitive call.

In high school football, the hand is the most commonly fractured body part, according to a study published in 2012 in The American Journal of Sports Medicine. More than 150,000 football players under age 15 seek treatment for injuries each year, and one out of every seven of those injuries are to the hand, finger, or wrist.

Whether it’s an arm cast, wrist splint or finger splint, many types of casts can help your recovery from surgery or an injury. Casts are hard, made with plaster or fiberglass, while splints are lighter and can be taken on and off more easily. These are important to protecting you while your injury heals, so follow these tips to take good care of your cast or splint:

Keep your cast or splint clean and dry. Getting it wet could irritate your skin. Cover it with a plastic bag, seal it with tape or rubber bands to keep it dry, and elevate it overhead while showering.

Do not let dirt, sand or other materials get inside your cast or splint.

Do not stick objects in your cast. If you feel itchy, ask your doctor for advice.

Never attempt to trim your cast. If there are rough edges or your skin is irritated around the ends, contact your doctor.

Contact your doctor if your cast or splint has a crack or soft spot.

Never attempt to remove a cast yourself.

Be sure to contact your doctor if you have worsening pain, excessive swelling, numbness or tingling in your fingers, burning or stinging, or loss of movement in your fingers while wearing a cast. Learn more about casts and splints at www.HandCare.org.

Dr. Tamara Clancy answers your questions about thumb arthritis, also known as arthritis base of the thumb.

What is the painful bump at the base of my thumb?

This is more than likely wear-and-tear arthritis, and the bump is one of the bones (metacarpal) that becomes prominent as the joint wears out (cartilage thins).

What is the cause?

The cause is the cartilage in the joint thinning out. Some of this is genetic (inherited). Injury and joint laxity (being “double-jointed”) may contribute to developing this as well. It is also more common in women.

Is there any way to know if my pain will get worse?

No — this is a problem that usually gets worse as we get older, but there is no way to predict how rapidly the pain will progress in a particular person.

Longtime West Boca Medical Center and private practice hand surgeon Dr. Michael Joyner sees his share of holiday mishaps – cutting holiday appetizers or prepping dinner with arthritis or using too sharp a knife – and has sage advice on how to ward off hand injuries.

What has arthritis got to do with food preparation?

They don’t have a good hold or grip. A lot of times, they’ll get a cut or laceration. In the hand, it doesn’t bleed so much, but may a hit a nerve. Many times they’ll have a constant numbness or tingling.

Does it get worse?

The longer you wait, the less likely it will be repaired.

What should people do if this happens to them?

I would follow up with a hand surgeon and be evaluated in a timely fashion. That can make a difference in your treatment plan.

The HandCare Blog is managed by the American Society for Surgery of the Hand, the oldest and most prestigious medical specialty society dedicated to the hand and upper extremity. Visit www.HandCare.org for more information about conditions, injuries and treatment of the hand, arm, elbow and shoulder.